Доклады Академии наук Республики Таджикистан, том 63, №01-02, 2020 г. |
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Download | Shabozov M.Sh., Palavonov K.K. | 5-14 | Inequalities of the Jackson-Stechkin and solving some extreme problems in L |
The work has found the exact values of the extremal characteristics of a special type, containing not only the generalized modulus of continuity, but also the value of the specified modulus of continuity averaged with the weight u(t - u)/t, 0 £ u £ t. The obtained result is the extension of one well-known theorem of S.V.Vakarchuk for the generalized modulus of continuity under consideration. |
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Key words: the best approximation; modulus of continuity; extreme characteristic; Steklov function; n-widths. | |
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Download | Mustafokulov R., Mirzoev J.A. | 15-23 | Study of non-model equation of type Euler of the fourth order |
The article considers a generalized form of a linear fourth-order Euler differential equation, constructs the corresponding model equation, which, by changing the variable, is reduced to an equation with constant coefficients. The connection between the solutions of the model and the corresponding non-model equation is established. |
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Key words: linear Euler equation; model equation; Cauchy function; Volterra-type integral equation. | |
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Download | Abdukarimov M.F. | 24-33 | On solvability of one combined mixed problem for a telegraphic equation with a variable coefficient |
In this paper, we study one mixed problem for a telegraph equation with a variable coefficient. Under certain conditions, the solvability of the considered mixed problem is proved. In addition to solvability, it is substantiated in the work that the solution of the problem under study is stable with respect to the additive perturbation of the coefficient, as well as to the boundary conditions. |
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Key words: telegraph equation; mixed problem; solvability; integral identity; stability. | |
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Download | Gulboev B.J. | 34-42 | Accounting diffusion of components mixture during filtration combustion of gases |
The relationship for the velocity of a stationary combustion wave is considered, taking into account the diffusion coefficients of the components of the gas mixture. The effect of these coefficients on the characteristics of the combustion wave of hydrogen, methane, and propane-air mixtures was study. It is established that taking into account the diffusion coefficients of the components contribute to a decrease in the wave propagation velocity and an increase in temperature in the combustion zone. This is most pronounced in the case of the temperature dependence of the diffusion coefficients of the components. |
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Key words: burning wave; wave speed; diffusion coefficient; combustion temperature; selective diffusion; hydrogen; methane; propane. | |
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Download | Usmanov Z.D. | 43-48 | About anagrams of word-form N-grams |
A systematic approach is proposed to automate the processing of a text collection for possible detection of anagrams for a pre assigned N-gram and also all anagrams for all kinds of N-grams. |
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Key words: text; word form; N-gram; anagram. | |
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Download | Usmanov Z.D., Kosimov A.A. | 49-54 | On the automatic identification of authors and styles of works of tajik-persian artistic literature |
Based on application of the γ-classifier to processing 68 works of 7 literary schools, estimates of the recognition efficiency of authorship and styles of Tajik-Persian literature are computed. |
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Key words: Indo-Iranian languages; authorship; style; identification. | |
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Download | Kokhirova G.I., Ivanova О.V., Buriev A.M., Rakhmatullaeva F.Dzh., Khamroev U.Kh. | 55-60 | Determination of the coordinates and orbit of the asteroid Don Quixote by observations in the Sanglokh observatory |
The results of astrometric processing of optical observations of asteroid (3552) Don Quixote, performed at the Sanglokh observatory in July 2018 are presented. Coordinates, apparent trajectory are defined and asteroid orbit is calculated. It is shown that the accuracy of astrometric measurements does not exceed 0.80 and 0.57 arc seconds in right ascension and declination of the object respectively. New results are in good agreement with the available dynamic data. It is shown that, despite the detected outburst, the asteroids orbit is stable, which indicates that a possible collision with another object was not catastrophic and did not lead to a significant change in the orbit. |
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Key words: asteroid; observations; astrometry; coordinates; accuracy; trajectory; orbit. | |
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Download | Umar Z., Qurbonien M.S., Rahimi F. | 61-68 | Quantum-mechanical calculation of the electronic structure of CaAlO:Mn within density functional theory |
Calculations of the electronic structure of CaAlO:Mnare presented with various calculation schemes - GGA, GGA+U, mBJ and mBJ+U within WIEN2k code. The electronic structure calculations were carried out using the full-potential (linearized) augmented plane-wave (LAPW) + local orbitals (lo) method. It has been found that the crystal field 10Dq parameter expands with increasing parameter U. |
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Key words: CaAlO nanocrystal; electronic structure; method DFT; schemes of calculation; GGA; mBJ; DFT+U. | |
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Download | Solikhov D.K., Dvinin S.A., Nurulhakov Sh.S. | 69-77 | Angular dependence of convective threshold instability and gain coefficient for opposite interacting waves |
In this article the dependence of convective threshold instability and gain coefficient for opposite interacting waves we have investigated. It is shown that the convective threshold instability and gain coefficient for opposite interacting waves increases, if the angle of scattering takes the value from (π/2 |
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Key words: stimulated Raman scattering; stimulated Brillouin scattering; ion-acoustic wave. | |
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Download | Mulloev N.U., Lutfiloev N.A., Odinaev S., Dergacheva M.I., Lavrik N.L. | 78-84 | Comparative analysis of spectral characteristics of humic acids of various genesis |
The IR spectra of 3 samples of humic acids of HA extracted from soils of different geographical zones were obtained. Analysis shows that all HA samples contain hydroxyl, aromatic, carboxyl, carbonyl groups and other groups. An analysis of the values of spectral coefficients shows the possibility of obtaining information about the structural features of HA macromolecules. Moreover, hydroxyl, carbonyl, etc. are used as the absorption coefficient. groups to the optical density of the carbonyl group. |
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Key words: IR-spectra; humic acids; absorption bands of hydroxyl; aromatic and carbonyl groups. | |
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Download | Boboev T.B., Istamov F.Kh., Gafurov S.J. | 85-88 | Laws of photochemistry in polymers |
The effect of preliminary UV irradiation with light with wavelengths λ = 254 nm, λ = 313 nm and λ = 365 nm on the molecular structure of PET samples of different thicknesses was studied. It was found that with an increase in the time of preliminary UV irradiation, the decrease in the relative optical density depends on the thickness of the sample. It was found that at thicknesses of 12×10 m, an apparent anomalous effect is observed. When taking into account the constancy of the radiation dose and the distribution of the radiation intensity over the thickness of the sample, the apparent anomalous effect disappears. |
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Key words: polyethylene terephthalate; UV radiation; relative optical density; photochemistry; light penetration depth. | |
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Download | Soliev L., Jumaev M.T. | 89-97 | Structure phase complex of the system
NaSO-KSO-MgSO-CaSO-HO at 0°С |
The structure of the phase complex of a five-component NaSO-KSO-MgSO-CaSO-HO system at 0°С using the translation method was studied. It was found that the system under study at this temperature by the presence of 3 non-invariant points, 10 monovariant curves and 12 divariant fields is characterized. Based on the obtained data, a diagram of the phase complex (phase diagram) of the studied system is constructed, which is fragmented along the crystallization regions of individual equilibrium solid phases. |
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Key words: translation method; diagram; phase complex; invariant points; monovariant curves; divariant fields. | |
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Download | Otaev Sh.D., Mirzoev D.Kh., Kayumov A.M., Jamolov N.M., Mirsaidov U.M. | 98-101 | Kinetics of the nitric acid decomposition of kaolin clays with preliminary sintering with sodium hydroxide |
The kinetics of the nitric acid decomposition of the kaolin clay of the Chashma-Sang deposit with preliminary sintering by sodium hydroxide has been studied. The activation energy of the process has been found, which for AlO amounted to 28.36 kJ/mol, that refers to a mixed, close to the diffusion region, and for FeO - 27.79 kJ/mol, which also refers to a mixed, close to the diffusion region. |
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Key words: kaolin clay; kinetics; nitric acid; decomposition; sintering; sodium hydroxide; mixed diffusion region. | |
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Download | Fayziev A.R., Mirakov M.A., Safaraliev N.S., Safarov L.J. | 102-107 | Aurikhalcite from skarno-magnetic deposit Middle Kharangon (Central Tajikistan) |
In the zones of oxidation of the skarn-magnetite deposit Middle Harangon, a relatively rare zinc and copper carbonate, aurichalcite, was found and described. |
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Key words: aurichalcite; deposit; Middle Harangon; spherulite; mineral; magnetite. | |
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Download | Mirakov M.A., Pautov L.A., Fayziev A.R., Shodibekov M.A. | 108-112 | Zircon of the Namangut pegmatite field
(South-Western Pamir) |
In this article the zircon from the Namangut pegmatite field are described. A characteristic feature of this mineral is the increased content of hafnium and uranium in it. |
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Key words: zircon; Namangut; pegmatite; crystal; chemical composition; hafnium; energy-dispersive spectrum. | |
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Download | Ergashev A., Sattarov B.N., Avezov T., Solieva B.A., Oyzoda N.Kh., Khakimova R.Sh., Saidnabiev M.M., Abdullaev Kh.A. | 113-118 | Water status of cotton plants after defoliation |
In this paper the results of study of the main indexes of water status of long-stable cotton after partial and full plants defoliation are presents. It is shown that the water content is little changed the level from defoliation. Ascertains that by increase the level of defoliation in experimental plants the intensity of transpiration is lowering. Is discovery that between leaf area and intensity of transpiration exist the higher direct negatively correlation. In partial and full removal the main of top driving of water flow-leaves in defoliated cotton plants considerable increase of real water deficit. |
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Key words: long-stable cotton; water status; water contents in the leaf; transpiration; water deficit; water keeping ability. | |
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Download | Niyazmuhamedova M.B., Rahimov M.M. | 119-123 | Content of protein and gluten (gluten) in wheat growing,
in the conditions of boghara (non irrigable land) |
In this article the results of determining of protein content and gluten in flour and grain in wheat of local selection and introduced from Russia. A comparative analysis of the grain of different varieties of wheat, local breeding and introduced from Russia to Tajikistan, showed a difference in the synthesis of protein and gluten depending on environmental and climatic factors. The grain harvest of the 2-nd year of the study had a high protein and gluten content, which is typical for strong wheat varieties. |
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Key words: wheat; flour; grain; protein; gluten (gluten); bread; bogara. | |
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Download | Muhabbatov D.K., Rasulova S.I., Amirov Sh.A., Muzafarova P.S. | 124-128 | Improving long-term results of postpartum anal sphincter rupture |
In the course of retrospective analyzes of postpartum anal sphincter insufficiency, along with well-known causes of poor long-term results of surgical treatment of postpartum anal sphincter insufficiency, 12% of patients had internal sphincter dysfunction and 52.5% had complicated forms of the disease. Timely diagnosis and correction of dysfunction of the internal sphincter of the rectum and using of combined methods of operations improve the long-term results of surgical treatment of patients with postpartum perineal rupture. |
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Key words: sphincterolevatoroplasty; postpartum rupture of the perineum; postpartum insufficiency of the anal sphincter; external sphincter; internal sphincter of the rectum. | |
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Download | Karim-zade Kh.D., Aripov A.L. | 129-134 | Spectrum of pyrotechnic eye injuries in children in Tajikistan |
In this article the clinical and epidemiological features of children's pyrotechnic eye injury in Tajikistan is discussed. The rate of pediatric eye injuries decreased from 5.6 to 2.9 per 1 million children after the introduction of a ban on the import and sale of pyrotechnic products in 2008. Of the 29 children with trauma, 24.1% developed unilateral blindness, of which 7% showed complete irreversible loss of vision in the affected eye. Unsatisfactory functional results were associated with penetrating injuries in the cornea, the presence of intraocular foreign bodies and the development of cataracts. In order to stop pyrotechnic eye injuries, blindness and low vision as a result of them, it is necessary to tighten control on the import and sale of pyrotechnic products, as well as raise public awareness of possible devastating side effects of their use. |
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Key words: pediatric eye injury; children; fireworks; clapperboard; sparkles; pyrotechnic injuries; open globe injury; closed globe injury; intraocular foreign body; blindness; visual impairment. | |
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